Okey dokey.... My suggestion would be to track down a food service place & get some ovenable things from there, it will make your job heaps easier with so many people to cater for. I used to work for PFD Foods in Sydney & they originated in Melbourne so you'd be able to find them pretty easily.

From there I'd suggest things like ****tail quiche, spring rolls, samosas, pastizzis, meatballs, mini chicken wings..... I could go on for ages! All of them are easy to make - just chuck them in the oven!!